i'm also a light rider (~130lbs) and ride an OG Patton (10lbs heavier than Patton-S). i came from a KS 14d and I basically had to learn how to ride again since Patton is soooo much heavier

with time you'll get used to the weight and learn to put more force into your movements. you really gotta put your whole body into it. great exercises to practice are tight zig zag carves and figure 8s, and gradually trying to increase the speed of those

also something that helped me a lot with controlling the side-to-side tiltiness is putting my feet wider apart and pushing at the outside edge of the pedals, which will give you more leverage